﻿Shader "Custom/SingleTexture"
{
    Properties
    {
        _Color ("Color", Color) = (1,1,1,1)
        _MainTex ("Main Tex", 2D) = "white" {}
        _Glossiness ("Smoothness", Range(0,1)) = 0.5
        _Metallic ("Metallic", Range(0,1)) = 0.0
    }
    SubShader
    {
        Pass{
        Tags{"LightMode" = "ForwardBase"}
        CGPROGRAM
        #pragma vertex vert
        #pragma fragment frag
        #include "Lighting.cginc"
        fixed4 _Color;
        sampler2D _MainTex;
        float4 _MainTex_ST;
        fixed4 _Specular;
        float _Gloss;

        struct a2v{
            float4 vertex : POSITION;
            float3 normal : NORMAL;
            float4 texcoord : TEXCOORD0;
        };
        struct v2f{
            float4 pos : SV_POSITION;
            float3 worldNormal : TEXCOORD0;
            float3 worldPos : TEXCOORD1;
            float2 uv : TEXCOORD2;
        };

        v2f vert(a2v v){
            v2f o;
            o.pos = UnityObjectToClipPos(v.vertex);
            o.worldNormal = UnityObjectToWorldNormal(v.normal);
            o.worldPos = mul(unity_ObjectToWorld, v.vertex).xyz;
            o.uv = v.texcoord.xy * _MainTex_ST.xy + _MainTex_ST.zw;
            // o.uv = TRANSFORM_TEX(v.texcoord, _MainTex);
            return o;
        }

        fixed4 frag(v2f i) : SV_Target{
            fixed3 worldNormal = normalize(i.worldNormal);
            fixed3 worldLightDir = normalize(UnityWorldSpaceLightDir(i.worldPos));
            //Use the texture to sample the diffuse color
            fixed3 albedo = tex2D(_MainTex, i.uv).rgb * _Color.rgb;
            fixed3 ambient = UNITY_LIGHTMODEL_AMBIENT.xyz * albedo;
            fixed3 diffuse = _LightColor0.rgb * albedo * max(0, dot(worldNormal, worldLightDir));
            fixed3 viewDir = normalize(UnityWorldSpaceViewDir(i.worldPos));
            fixed3 halfDir = normalize(worldLightDir + viewDir);
            fixed3 specular = _LightColor0.rgb * _Specular.rgb * pow(max(0, dot(worldNormal, halfDir)), _Gloss);
            return fixed4(ambient + diffuse + specular, 1.0);
        }
        ENDCG
    }
    }
    FallBack "Diffuse"
}
